Desktop background picture resolutions with extended desktop

[tfboy]

I'm working at a place where I have the use of a nice external screen with a 2560x1600 resolution.
My laptop's native screen resolution is 1600x900

Whilst I can get the external monitor's resolution set to its native 2560x1600, I cannot seem to get a desktop background picture using the resolution.

The resolution seems to be fixed by the resolution of the primary display (my laptop) when I choose fit, fill or stretch: the edges of the photos are centered in a window that's 1600x900 in size.

If I change the primary display to be the external screen, then the picture will fill (the photos I'm using are much larger resolution) which solves the problem, except that I want my laptop's screen to remain the primary display.

Is there anyway around this strange limitation? Ideally I'd like the picture to filled or fitted to the higher resolution screen whilst retaining my laptop's screen as the "primary" one.

[Kanoe]

Could you choose background pictures that are natively 2560x1600 in size or above and use the centre option so that on the smaller res screen the edges will be cut off but will fill the entire second screen nicely?

I do this when running my 4k and 1920x1200 dual monitor setup.

[tfboy]

Thanks, sounds like it's the best compromise out there

[jag272]

There is also this as an option if you don't mind 3rd party tools.

http://dualmonitortool.sourceforge.net/

Came across it myself as I recently got dual monitors, lets you set independent wallpapers on each monitor or stretch one across both, so I suspect it would allow for the use of 2 different sized images, but I haven't actually got round to installing it yet to fiddle with it. Might be worth a look.